问题如下：
White wants to know how seasons influence the sales of the down jacket. Then he builds a regression model which uses a dummy variable (1 for winter and 0 for summer) as independent variable and the sales volume (thousand) as the dependent variable and gets the following results:
What is the difference between the sales volume in summer and in winter in thousand?
选项：
A.10.3958
B.20.5732
C.3.7642
解释：
B is correct.
考点: Dummy variable.
解析:本题的自变量季节为虚拟变量，1代表冬天，0代表夏天。由表中的自变量的系数可得，冬天比夏天的销量要高出20.5732千件，即冬天与夏天销量的差异为20.5732千件。选择B选项。
请问老师这个表怎么理解，方程应该是y=20.5732x + 3.7642？截距和虚变量的标准误和 T 检验统计量有什么用？
